CHANGING THE RULES
OF INFRASTRUCTURE DESIGN

Changing the rules to a performance-based approach means that designers need to take responsibility for their work, but the payoffs can be huge.

In the master planning phase of New York’s Second Avenue Subway, Andrew Wisdom was responsible for changing the rules by introducing a performance-based design approach. By convincing the project’s client to accept the idea of approaching the design from operational first principles rather than on the basis of rules of thumb entrenched in design codes, the design team was able to save many millions of dollars in projected construction costs.

The project’s master planning was in danger of being compromised by rigorous application of the code-based approach accepted for design of all transit infrastructure in New York. This approach meant designers were unable to take into account the unrealistically compounding effect of applying numerous factors of safety to the design process, which resulted in over-provision of staircases and escalators in the underground stations. In response to this and as lead transportation planner responsible for all passenger space planning, Andrew developed an alternative performance-based approach to the design and (this was the difficult bit) was able to get everyone in the design process to agree to changing the rules from the business-as-usual code-based approach with which everyone was familiar.

Adoption of this approach allowed the design team to limit the provision of staircases and escalators to a realistic number, which in turn avoided the need for excessively wide platforms to cater for unnecessary staircases and escalators. This allowed the station boxes to be sized realistically, with associated substantial savings in construction costs.